Peanut, cotton crop conflicts under study

It's a question that has weighed heavy on the minds of farmers in the lower Southeast for many years. Can we — and should we — plant cotton early enough so it can be harvested before peanuts?

“In years past, we've always talked about wanting endurance in our cotton crop — we want a full-season crop,” says Steve M. Brown, University of Georgia Extension cotton specialist. “And yet, especially if we factor peanuts into the whole farm operation, we do need to think about the possibility of harvesting cotton early.”

There are several reasons, says Brown, why a farmer might want to consider an early management system for cotton.

“Tomato spotted wilt virus has a profound impact on when we plant peanuts. In past years, growers typically planted peanuts in mid-April. Now, the ideal planting date for peanuts has moved to mid- and later-May, so that growers can minimize their risk to this terrible problem,” he says.

The 2004 University of Georgia Tomato Spotted Wilt Risk Index for Peanuts recommends the ideal planting date for peanuts as May 11-25. The greatest risk to the virus, according to the index, comes if you plant before May 1.

“What has happened with this later planting of peanuts is that we have peanuts and cotton being planted at the same time, and they're ready to harvest at the same time. And agronomically and physiologically, we absolutely had to get the peanuts out before we got into cotton,” says Brown.

Another good reason for an early management cotton production system is that a range of maturities can spread out harvest, he adds. “Even in the absence of peanuts, and with the multiple varieties of cotton, we like to think about spreading out our harvest and not have all varieties ready and needing to be picked at the same time,” he says.

There are obvious risks to planting cotton earlier, notes Brown, and for that reason, growers should consider planting only a small portion of their crop for earliness.

“You should consider planting only 10 to 20 percent of your cotton acreage for harvest prior to Sept. 20. You want to minimize the potential losses of yield and quality.”

Looking at planting and harvest dates based on a 140-day season, a crop planted on April 15 will be harvested Sept. 2, a crop planted May 1 will be harvested Sept. 18, a crop planted May 15 will be harvested Oct. 2, and a crop planted May 25 will be harvested Oct. 12.

Historical rainfall data shows that mid- to late-October traditionally is the ideal time for harvesting either cotton or peanuts.

“The point is, if you back up peanut planting, and you get into cotton harvesting, you're going to push everything on top of each other, and you'll have cotton sitting in the field, losing quality and yield.”

In an early management system, growers should manage a cotton crop for harvest prior to Sept. 20, says Brown. “We don't want to plant too early, but we need to plant at about April 15-20. We want to use growth regulators to encourage earliness. We want to avoid excessive nitrogen and not over-fertilize to encourage rank growth. We want the process to be winding down at about the middle to latter part of August.”

Growers in an early management system also want to avoid early-season fruit losses from pest management mistakes such as the misapplication of glyphosate and losses to plant bugs, says Brown.

“And as the crop reaches that 60-percent open level, we need to be aggressive with our defoliant and boll opener and get the crop out. Be prepared to apply these materials from about Aug. 20 to Sept. 5. One of the major problems we have with cotton in Georgia is that we don't get the crop out as quickly as we should. We don't spray our harvest-aid products quickly enough and we don't pick the crop as rapidly as we should.”

Brown reminds growers that there are risks to an early management system for cotton in Georgia. “If we plant too early in April, we may encounter stand problems and diseases related to cool temperatures.

“Likewise, if you look at the historical numbers, Labor Day plus or minus 10 days is a key time for a rainfall event and there could be problems with boll rot, hard lock and reduced color grade. But that's no more of an issue than having cotton ready to be picked in mid- to late-September and still waiting a month before picking.”